Hypertonic hydroxyethyl starch solution for hypovolaemia correction following heart surgery

Background. The aim of the study was to evaluate the effect of hypertonic NaCl hydroxyethyl starch solution on haemodynamics and cardiovascular parameters in the early postoperative period in patients for correction of hypovolaemia after heart surgery. Methods. Eighty patients undergoing myocardial revascularisation at the Clinic of Cardiac Surgery of the Heart Centre (Kaunas University of Medicine) were randomly divided into two groups. The HyperHaes® group (n = 40) received 250 ml 7.2% NaCl/6% HES solution and the control Ringer's acetate group (n = 40) received placebo (500ml Ringer's acetate solution) for volume correction after the surgery. Results. After infusion of HyperHaes® solution, cardiac index increased from 2.69 (0.7) to 3.52 (0.8)l/min/m2, systemic vascular resistance index, pulmonary vascular resistance index and the gradient between central and peripheral temperature decreased, and oxygen transport parameters improved. Ringer's group patients needed more intensive infusion therapy (4050.0 (1102.2) ml in the Ringer's group, 3513.7(762.5) ml in the HyperHaes® group). During the first 24 hours postoperatively, diuresis was significantly higher in the HyperHaes® group (3640.0 (1122.9) ml and 2736.0 (900.7) ml), total fluid balance was lower in HyperHaes® group (1405.6 (1519.0) ml and 2718.3 (1508.0) ml, respectively). After the infusion of HyperHaes ® solution, no adverse events were noted. Conclusions. HyperHaes ® solution had a positive effect on haemodynamic parameters and microcirculation. Oxygen transport was more effective after HyperHaes® solution infusion. Higher diuresis, lower need for the infusion therapy for the first 24 hours and lower total fluid balance were determined in the HyperHaes® group. No adverse effects were observed after HyperHaes® solution infusion. Perfusion (2007) 22, 121—127.

[A role of thoracic epidural anesthesia in pulmonary resection surgery]

This article presents a review of current literature on impact of thoracic epidural anesthesia on functions of organs and systems. Its role in anesthetic management of pulmonary resection is discussed. Thoracotomy is one of the most painful surgical procedures followed by intense, acute, and chronic pain associated with post-thoracotomy. Thoracic epidural anesthesia ensures adequate analgesia in postoperative period and assists in solving problem of chronic pain. Thoracic epidural anesthesia reduces systemic stress response by inducing sensory and sympathetic blockade. Pulmonary resection produces changes in respiratory function which may result in respiratory insufficiency and other pulmonary complications. During one lung ventilation, thoracic epidural anesthesia reduces pulmonary blood shunt and improves oxygenation. Postoperatively due to effective pain relief and improvement of diaphragm function, thoracic epidural anesthesia improves respiratory function, and rate of pulmonary complications is decreased. Sympathetic blockade during thoracic epidural anesthesia reduces the rate of perioperative myocardial ischemia and cardiac mortality. It also reduces the number of thromboembolic and gastrointestinal complications and has a positive effect on immune function. Due to numerous benefits, thoracic epidural anesthesia can be recommended as a standard in pulmonary resection surgery.

Influence of residual blood autotransfused from cardiopulmonary bypass circuit on clinical outcome after cardiac surgery

Autotransfusion of the residual blood from the cardiopulmonary bypass (CPB) circuit is considered to be one of the methods enabling reduction in the need for transfusion, the possible adverse effects of which are well known and documented. The aim of the study was to evaluate the effectiveness of the autologous autotransfusion of centrifuged red blood cells from the residual blood of the CPB circuit in patients following heart surgery. Three groups of patients who underwent heart surgery were examined. The first group (Group 1) consisted of 37 patients who received all of the residual blood in the bypass circuit after CPB (collected into sterile plastic bags) during the early postoperative period. The second group (Group 2) consisted of 45 patients who did not receive the residual blood following CPB. The third group (Group 3) consisted of 42 patients who underwent reinfusion of centrifuged red blood cells from the residual blood remaining in the CPB circuit during the early postoperative period. Hematocrit (Hct) values 12 hours after the operation were found to be higher in Group 3 compared with those of the first and the second groups (by 13.2% and 11.1%, respectively). Blood loss during the first 12 hours after the operation and during the time spent in the intensive care unit did not differ between the groups. The number of transfusions was significantly lower in Group 3 (28.57%) in comparison with that of Groups 1 and 2 (37.83% and 38.10%, respectively). The rate of infective complications in Group 3 was lower in comparison with both Group 1 and Group 2 (9.2% and 18.1%, respectively). The duration of in-hospital stay in Group 3 was 25.8% shorter than Group 1. We conclude that autotransfusion of centrifuged red blood cells processed from the residual blood of the CPB circuit after CPB was effective in increasing Hct values 12 hours postoperatively, reducing the need for donor blood product transfusions, the rate of infective complications and lenght of stay in hospital.

[Minimal effective dose of spinal hyperbaric bupivacaine for adult anorectal surgery: a double-blind, randomized study]

The aim of the study was to find minimal effective dose of spinal hyperbaric bupivacaine for adult anorectal surgery.

METHODS

The study included 93 adult consecutive patients admitted for anorectal operations. Dural puncture was made before surgery in the sitting position at L3-L4 or L4-L5 with 25-26G Tamanho spinal needle (BBraun, Germany) and different volumes of hyperbaric bupivacaine (Marcaine Spinal Heavy 0.5%, AstraZeneca) were injected over 2 minutes: group 1 (n=17) 1.5 ml, group 2 (n=38) 1.0 ml, group 3 (n=38) 0.8 ml. After sitting for 10 minutes patients were asked to lie down and surgery was started. Following variables were assessed: rate of success, level and duration of sensory and motor block, time to voiding and ambulation, complications, consumption of analgesics, quality of anesthesia according to the patient and medical staff.

RESULTS

Groups were comparable in demographics. No case of failure was registered but 4 patients (10.5%) in the group 3 received supplemental i/v fentanyl to treat tension in the abdomen intraoperatively. Level of sensory block in groups 1, 2, 3 was 10.4+/-1.7, 7.013+/-2.2, 6.7+/-1.9 dermatomes, respectively (p<0.0001 ANOVA; p<0.0001 group 1 vs 2, group 1 vs 3, p=1.0 group 2 vs 3, Bonferroni). Extent of motor block was 2-3 scores according to the Bromage scale in 70.5% of group 1 cases, compared to 0-1 score in 97.3% of group 2 and 92.1% of group 3 cases. Median (range) duration of motor block in groups 1, 2, 3 was 90 (0-120), 0 (0-90), and 0 (0-60) min, respectively (p<0.0001 ANOVA; p<0.0001 group 1 vs 2, group 1 vs 3, p=0.13 group 2 vs 3, Bonferroni). Time of ambulation was 181.5+/-41.5, 136.6+/-32.2 and 123.0+/-45.9 min, respectively (p<0.0001 ANOVA; p<0.001 group 1 vs 2, p<0.00001 group 1 vs 3, p=0.43 group 2 vs 3, Bonferroni). There was no significant intergroup difference in time to urinate; retention developed in 20.4% of total cases. No difference was found in morphine consumption, 64.5% of cases did not require rescue analgesics. Quality of anesthesia was stated as excellent by the anesthesiologist and surgeon in all groups. However, quality was rated as excellent by patient in the operating room in groups 1, 2, 3: 58.8, 94.7, and 86.8%, respectively (p=0.003), on day 1 postoperatively: 76.5, 92.1, and 97.4%, respectively (p=0.023); by nursing staff: 82.4, 100, and 97.4%, respectively (p=0.019). Lower rates in group 1 were due to extensive motor block. In conclusion, a minimal recommended dose of spinal hyperbaric bupivacaine for anorectal surgery is 4-5 mg; a dose of 7.5 mg is excessive due to prolonged sensory and motor block.

[Bupivacaine for continuous interscalene brachial plexus analgesia after shoulder surgery]

OBJECTIVE

This study evaluates clinical efficacy of continuous interscalene brachial plexus block with bupivacaine 0.15% for postoperative analgesia after shoulder surgery.

MATERIAL AND METHODS

Eighty patients, scheduled for elective shoulder surgery, were included in this study. All patients received an interscalene block before surgery. A perineural catheter was then introduced for continuous brachial plexus analgesia. Patients were prospectively randomized in a double-blinded fashion to receive either bupivacaine 0.15% or placebo postoperative infusion through an interscalene catheter. Pain was assessed with a visual analog scale at rest and also in motion. Duration of surgery and surgery type, satisfaction scores, supplemental analgesia, side effects, circulatory and respiratory parameters were recorded.

RESULTS

The bupivacaine group showed less pain at rest and in motion than the placebo group (p<0.0001), except 4 and 6 h after the brachial plexus block; a requirement for supplemental analgesia was also lower. Side effects (except weakness in the arm, which was more frequent in bupivacaine group), circulatory and respiratory parameters were comparable in both groups. Satisfaction scores were higher in bupivacaine group.

CONCLUSIONS

Continuous interscalene brachial plexus analgesia is a reliable and effective method of providing postoperative pain relief after shoulder surgery and is superior to the systemic analgesia.

Anesthesia for ambulatory anorectal surgery

The prevalence of minor anorectal diseases is 4-5% of adult Western population. Operations are performed on ambulatory or 24-hour stay basis. Requirements for ambulatory anesthesia are: rapid onset and recovery, ability to provide quick adjustments during maintenance, lack of intraoperative and postoperative side effects, and cost-effectiveness. Anorectal surgery requires deep levels of anesthesia. The aim is achieved with 1) regional blocks alone or in combination with monitored anesthesia care or 2) deep general anesthesia, usually with muscle relaxants and tracheal intubation. Modern general anesthetics provide smooth, quickly adjustable anesthesia and are a good choice for ambulatory surgery. Popular regional methods are: spinal anesthesia, caudal blockade, posterior perineal blockade and local anesthesia. The trend in regional anesthesia is lowering the dose of local anesthetic, providing selective segmental block. Adjuvants potentiating analgesia are recommended. Postoperative period may be complicated by: 1) severe pain, 2) urinary retention due to common nerve supply, and 3) surgical bleeding. Complications may lead to hospital admission. In conclusion, novel general anesthetics are recommended for ambulatory anorectal surgery. Further studies to determine an optimal dose and method are needed in the group of regional anesthesia.

[Interscalene brachial plexus block for shoulder surgery]

OBJECTIVE

This study evaluates the clinical efficacy of interscalene brachial plexus block (according to G. Meier) for shoulder surgery.

PATIENTS AND METHODS

Seventy-three patients, scheduled for the elective shoulder surgery, were included in this study. All patients received an interscalene block before surgery and a standard analgesia protocol after it. Minimal stimulating current, block performance time, the onset of sensory and motor blocks, duration of surgery and surgery type were recorded. The quality of nerve block was also evaluated by a surgeon. The duration of postoperative analgesia resulting from residual local anesthetic effect was expressed as the time to first requirement for post-operative pain medication. Satisfaction scores with a visual analog scale, side effects, circulatory and respiratory parameters were assessed.

RESULTS

The success rate was 97%. For the nerve location a minimal stimulating current of 0.1 mA had been achieved. The median onset time of both motor and sensory blockade was <4 min. A complete muscle paralysis was observed after 21 (16-30) min. Duration of sensory blockade was 420 (240-840) min. The time from the block placement to the first request for pain medication was 8 (4-32) hours. Side effects were minor. Patient satisfaction was high.

CONCLUSIONS

Single injection interscalene brachial plexus block is a reliable anesthetic and effective method of providing postoperative pain relief after shoulder surgery.

[Regional anesthesia for patients with cardiac diseases]

This review explores the effects of central neural blockade on cardiovascular system in healthy patients and for patients with common cardiovascular disease (ischemic heart disease, rheumatic valve disorders, cardiomyopathy). Central regional blockade poses these patients at some extent of risk due to possible hemodynamic instability because of effects of blockade on peripheral vessels and heart. High epidural anesthesia has favourable effects on coronary vessels. It increases diameter of epicardial coronary stenosis, reduces the ST segment depression, provides pain relief for patients with unstable angina, does not affect myocardial contractility. Recommendations are made about applying the central regional anesthesia for these patients; prevention and treatment of hypotension are discussed; and peculiarities of central regional anesthesia for patients taking anticoagulants are highlighted.

[Comparison of two different methods of analgesia. Postoperative course after colorectal cancer surgery]

BACKGROUND

The purpose of our study is to compare two methods of postoperative analgesia in colorectal cancer patients after resectional operations, and to evaluate advantages and limitations of each method on the postoperative course of these patients.

METHODS

One hundred patients scheduled to undergo elective colorectal cancer surgery were randomized into two groups; after general anesthesia, one group received epidural analgesia (n=50) and the second one - intramuscular pethidine analgesia (n=50). Visual analogue scale at rest and on coughing was used to compare intensiveness of pain between the two groups during the day of surgery and first three postoperative days. Patients' mood and self-satisfaction were evaluated using self-assessment manikin scale. Side effects of both analgesia techniques were registered. All complications and postoperative hospital stay were also evaluated.

RESULTS

Visual analogue scale pain scores at rest and on coughing were significantly better in epidural analgesia group as compared to systemic intramuscular pethidine analgesia group (p<0.05). Additional analgesics were needed for 10 (20%) and 28 (56%) patients respectively to keep visual analogue scale pain scores below 5. Adverse effects such as profound sedation, nausea and vomiting were more frequent in systemic intramuscular pethidine group, but pruritus - very uncommon to compare with epidural analgesia group (p<0.05). There were no significant differences between the two groups in respect to complications and postoperative hospital stay.

CONCLUSIONS

Epidural analgesia has demonstrated significantly better effectiveness than intramuscular pethidine analgesia after colorectal cancer surgery with fewer adverse events. Self-assessment manikin scores showed better self-satisfaction in patients of epidural analgesia group as compared to patients in systemic pethidine group.

[Comparison of electrocardiographic parameters during pneumoperitoneum in patients without cardiovascular diseases and in patients with ischemic heart disease]

Pneumoperitoneum induces significant pathophysiological changes. Changes in performance of cardiovascular system can be severe in patients with compromised cardiac function. Groups of patients to whom these changes may be deleterious are yet to be identified. Aim of the study was to elucidate the influence of pneumoperitoneum on the electrocardiographic recording.

PATIENTS AND METHODS

35 cardiovascular healthy (ASA I-II) patients (group 1) and 34 patients with underlying moderate ischemic heart disease (ASA II-IV, Goldman's cardiac risk class II-III) (group 2), scheduled for elective laparoscopic cholecystectomy, were included in the study. Premedication included sedatives for all patients and the group 2 received their usual cardiovascular treatment one hour before operation. A standardized protocol of monitoring and anesthesia was followed in the operating room. 12 lead electrocardiograms (ECG) were obtained before and after induction of anesthesia, every 10 minutes during pneumoperitoneum, after the peritoneal desufflation and after extubation. The ECGs were recorded and analysed by the means of computerized system for ECG record and analysis "Kaunas" (UAB "Kardiosignalas", Kaunas, Lithuania). The analysis was performed postoperatively.

RESULTS

During pneumoperitoneum a deviation of cardiac electrical axis to the left was observed. There were no marked changes in duration of P wave, P-Q interval, and QRS complex. Following abdominal insufflation a tendency to flattening of T wave was observed returning to the initial position after desufflation. No significant dislocation of ST segment was recorded.

CONCLUSIONS

The pneumoperitoneum induced changes of cardiac electrical axis can affect the interpretation of ECG seen on a cardiac monitor during anesthesia. Pneumoperitoneum does not pose patients with moderate ischemic heart disease at additional risk of developing myocardial ischemia.